Engineering interventions for enhanced sophorolipid biosynthesis: from native producers to recombinant platforms

Sophorolipid (SL) are glycolipid biosurfactants with growing industrial relevance as sustainable alternatives to petrochemical surfactants. This review highlights the advances in SL genetics and pathway architecture, transcriptional and process level regulation, and comparative performance of native producers versus recombinant platforms. It emphasizes the transition from empirical optimization to rational, systems guided strategies integrating advance metabolic engineering strategies including pathway optimization to divert carbon flux toward the SL module, balance redox/energy demands with growth, and tailor congener profiles. We further evaluated the current industrial feasibility, technology used by several companies highlighting progress increasing titers and productivities alongside persistent constraints in production, reliance on costly feedstocks, different fermentation methods, process parameters, and challenging downstream recovery. Key research gaps include incomplete understanding of regulatory control, limited systematic flux redistribution, and insufficient techno-economic integration. We outline future priorities for CRISPR enabled and omics guided rewiring, secretion and tolerance engineering, deployment of low cost/waste substrates, and standardized, scalable purification. These directions define a roadmap to robust, cost competitive SL manufacturing and clarify where recombinant hosts can complement or extend capabilities beyond Starmerella bombicola.